Playing in only her eighth tournament this year, Kvitova could be short of match practice but not confidence at the U.S. Open.

"I will try my best. It means a lot, it's an incredible night to play in front of a great crowd", Kvitova said in her on-court interview.

In the second set, Muguruza responded perfectly by breaking Kvitova in the opening game - but the lead did not last long as the world number 14 broke back.

In December, two-time Wimbledon champion Kvitova had her hand slashed when an intruder held her at knifepoint in her apartment in the Czech Republic.

But Kvitova played the big points well on her own serve and was rewarded moments later by hitting back. I'm sorry, I'm not sorry I beat her. "I think she's playing very well". But sometimes I just really feel that the touch is there, the strength, the aggressive kind of game plan.

However, the Czech survived three break points in a tense sixth game to remain within touching distance at 4-1, and she brought it back on serve a game later when converting with her first break point. I feel very happy.

By advancing to the Round of 16, Muguruza remains the front-runner for the No.1 ranking, having accumulated 6,030 points. Neither of them has been great in NY, with Kvitova reaching the quarterfinals once, and this being Muguruza's first 4th Round. "I'll keep on eye now on the scores, but that's it". Their most recent match, a third-round encounter at Wimbledon in 2014 that Kvitova won, 5-7, 7-6 (2), 7-5, is considered one of the best women's matches of the past decade. After winning that game, Muguruza gained a little confidence and definitely gave Kvitova a hard time closing the match out. Muguruza had chances to go 5-1, could not take them, and slowly Kvitova began to turn the screw.

She is in the Grand Slam quarterfinals for the first time since the 2015 United States Open.

"What she has gone through is unimaginable, unreasonable", Williams said. So for her, I think to be playing well is such a blessing.

IAEA: Iran Complying With Nuclear DealSep 02, 2017 - 00:56
As well as the United States the hard-fought agreement also includes China, Russia, Britain, France and Germany. Iran now has less than a third of the amount of enriched uranium that it's permitted to have under the JCPOA.

Merkel Opens Door to Diesel Lawsuits as Election Rival AttacksSep 01, 2017 - 01:56
She said that the spat between Warsaw and Brussels touches on "the basis of cooperation inside the European Union ". She said the policy was justified in that year because of the emergency situation during that particular period.

Robust Canadian growth boosts chances of rate hike as some eye SeptSep 01, 2017 - 01:54
The economists expect that the hurricane Harvey, which is now hitting Texas and Louisiana, weighs in on the economic growth. Despite almost uniform skepticism from mainstream economists, he insisted that much faster economic growth is within reach.

Taylor Swift took time off to reinvent herselfSep 01, 2017 - 01:51
West used a floating stage on his recent Saint Pablo Tour. "This has been her life for the past few months", said the source. However, most of these people were also once her friend as well. "I made that b***h famous".

Samsung's Gear Sport smartwatch puts fitness firstAug 31, 2017 - 01:25
The wireless Bluetooth headphones lets you listen to your favorite music as well as make and receive calls. It also features Running Coach function that provides in-ear audio exercise status updates in real-time.

Houston police officer drowns in floodwatersAug 30, 2017 - 01:50
Perez served on the force for 34 years and was now assigned to the traffic enforcement division. Chief Acevedo said, "Every day we ask men and women to show up in good and bad conditions".

Celtics, Cavs still expected to complete Kyrie Irving tradeAug 29, 2017 - 00:41
Still, it is unlikely that the Celtics could find a point guard of Thomas' stature on the market - never mind Irving's. If it comes to it, the Cavs could always void the trade and still negotiate with Boston on a revised deal.

Trump to present plan for reviving peace talksAug 28, 2017 - 01:14
Palestinian President Mahmoud Abbas will hold talks in Ankara on August 28 amid calls for the resumption of negotiations between the Palestinians and Israelis to end the conflict.

Manchester United vs. Leicester: Highlights and recapAug 27, 2017 - 01:08
United have scored eight goals in their first two league games this season, but Mourinho is not taking anything for granted. Not that Mourinho witnessed Rashford volleying in Henrikh Mkhitaryan's corner three minutes after he was introduced.